We investigate the extent to which a common currency basket peg would stabilize effective exchange rates of East Asian currencies. We use an AMU (Asian Monetary Unit), which is a weighted average of ASEAN10 plus 3 (Japan, China, and Korea) currencies, as a common currency basket to investigate the stabilization effects. We compare our results with another result on stabilization effects of the common G3 currency (the US dollar, the Japanese yen, and the euro) basket in the East Asian countries (Williamson (2005)). We obtained the following results: first, the AMU peg system would be more effective in reducing fluctuations of the effective exchange rates as more countries applied the AMU peg system in East Asia. Second, the AMU peg system would more effectively stabilize the effective exchange rates than a common G-3 currency basket peg system for four (Indonesia, the Philippines, South Korea and Thailand) of the seven countries. (The rest omitted)